1. Field of the Invention
This invention relates to a device and method for automatically changing printer drivers, more specifically, to a device and method which is capable of automatically searching for another appropriate printer driver stored therein when a printing error occurs with a preset printer driver wherein an integrated printer driver, which is a software, includes a plurality of printer drivers provided in various types to satisfy requirements depending on various computer environments.
2. Description of the Related Art
There is well known that communication between a computer and a printer is necessary to execute printing job and they are interconnected via an emulator making their communication possible. One of the emulators is a printer driver. Such printer drivers are provided in various types to satisfy many different computer environments depending on users and on production by printer manufacturers. Consequently, the printer drivers are compatible with various computer environments as well as various application programs and have unique properties for each.
In contemporary design practice a computer-printer system such as a Printing System Wherein One Of Printer Drivers Through Which Print Data Is Sent From A Data Processor To A Printer Is Selected Based On Interpreters Available On The Printer of I. Sasaki, U.S. Pat. No. 5,228,118, comprises a computer including a storage device, a display unit, a control unit and a transmit-receive interface device for printing; a local printer including a printing device and a transmit-receive interface device; and a communication line interconnecting the computer and the printer to communicate with each other.
In the storage device are stored printer drivers which operate according to hardware data of the local printer or a network printer, the type of operating system (e.g. DOS, Windows, UNIX, etc.) and application programs. The display unit exhibits a state of a printing process and an error message upon occurrence of an error. The transmit-receive interface device communicates with the local printer to transmit and receive data. The interface device has a time interrupt routine unit generating interrupt signals at fixed intervals to request a response from the local printer in order to sense a data transmitting state to the local printer and various error occurrences. When the time interrupt routine unit sends the response requesting signals to the local printer and does not receive any response therefrom, it sends signals indicating an occurrence of an error in the local printer to the control unit. Then, the control unit sends control signals directing the display unit to display a message indicative of the error occurrence in the printer.
The storage device, the display unit and the transmit-receive interface device are connected with the control unit via a data bus for controlling transmission of data and a control bus for controlling transmission of control signals. When the printer is connected to the computer a printer driver for controlling the printer is installed and stored in the storage device. This is the first connection between the computer and the printer. At this time, the control unit inputs fundamental information such as the type of printer, the types of the printer drivers, etc. into the storage device.
On receiving a print command, the computer-printer system calls the fundamental information, i.e. the type of the printer and the installed printer driver, which are stored in the storage device and attempts to control the printer. When the printer operational, the response requesting signals are sent at fixed intervals to the computer and the printer through the time interrupt routine unit of the transmit-receive interface device, thereby enabling a determination to be made regarding whether an error occurs in the computer or in the printer. If there is a determination that both the computer and the printer are operating normally the printing process proceeds and terminates upon completion. If, however, there is a determination that either the computer or the printer is not operating properly by not responding to the response requesting signals from the time interrupt routine unit, the control unit senses an occurrence of an error and determines the kind of error that has occurred. On occurrence of such errors, the control unit provides an indication of the error state to the operator by means of the printer or the display unit of the computer. Then, the operator determines the type of the error and if the error is due to a problem with the printer driver, determines whether there is another printer driver stored in memory which is capable of overcoming the error. The operation for selecting the appropriate printer driver is cumbersome and time-consuming. Furthermore it is not easy for the operator to find the cause of the error. This.results in low printing efficiency.
It is therefore an object of the present invention to provide an integrated printer driver which includes a plurality of printer drivers in a computer and a printer driver calling device for searching another appropriate printer driver among the plurality of printer drivers in the integrated printer driver when printing error occurs, and if there is a determination of the printer driver calling device that there is an appropriate printer driver capable of overcoming the error in the integrated printer driver, the printing job is continued with the newly selected printer driver without any manual operation for changing the printer drivers.
A method for achieving the above object determines the type of printing errors that occurred, selects from an integrated printer driver including a plurality of printer drivers and changes from a preset printer driver to a selected one of the plurality of printer drivers capable of overcoming the error, and sets the selected printer driver in order for the printer to be able to recognize the selected printer driver to continue a printing job.
An apparatus for achieving the above object in a computer-printer system 300 according to the invention utilizes a computer including a storage device having installed therein an integrated printer driver 25 into which are united a plurality of printer drivers and a plurality of types of errors that may occur in the computer or printer, a display unit for displaying the operational state of the computer or printer, a control unit and an integrated transmit-receive interface device for printing, a local (or network) printer, a communication line such as a bidirectional cable which enables the computer and printer to communicate with each other, and a time interrupt routine for requesting a response from the computer and the printer, such that no response provides an indication that an error has occurred. When an error occurs, the control unit determines the type of error and, if the error is due to an abnormal operation of a prime printer driver, selects another of the plurality of printer drivers to be set as the new prime printer driver.